Renewable grate-bar leaf.



APPLICATION FILED MAR. 16, 1905.

Patented Feb.15,1910.

I UUUUEIDEHJEIUUEJE] rte.

THOMAS S. JOHNSON, OF SCRANTON, PENNSYLVANIA, ASSIGNOR T SCRANTON STEAM PUMP COMPANY, OF SCRANTON, PENNSYLVANIA.

RENEWABLE GRATE-BAR LEAF.

Specification of Letters Patent. Application filed March 16, 1905.

Patented Feb. 15, 1910. Serial No. 250,391.

To all whom it may concern:

Be it known that I, THOMAS S. JOHNSON, a citizen of the United States of America, residing at Scranton, in the county of Lackawanna and State of Pennsylvania, have in vented certain new and useful Improvements in Renewable Grate-Bar Leaves, of which the following is a specification.

My invention relates to certain new and useful improvements in renewable grate bar leaves, in which the face or surface of the leaf which comes in contact with the fire is similar to an arc of a circle; and the objects of my improvement are, first, to provide a grate surface or plurality of leaves the contour of which is such that during the process of cleaning the fires the ashes and live coals are not mixed; second, to provide means for cutting the clinker to a size sufficiently small to pass between the bars; third, to facilitate the renewal of a great or small area of the surface as may be desired; and fourth, to provide an equally distributed air space of greater area than could be secured by the use of a leaf of the flat surface type.

With the above and other objects in view, my invention has for its further object, si1n plicity in construction, the elimination of as many parts as is possible, and economical manufacture.

Referring to the accompanying drawings forming a part of this application and wherein like numerals of reference indicate similar parts throughout the several views, Figure 1, is a view in perspective of my im proved grate bar leaf. Fig. 2, is a plan view of the same drawn to a small scale, the dotted lines showing the webbed shank and tapered openings for air space. Fig. 3, is a perspective view of a modification thereof. Fig. 4, is a perspective view of a modification of my leaf, to be used in grates for burning bituminous coal, the dotted lines showing how the face may be extended. Fig. 5, is a perspective view in part diagrammatic showing a part of the frame, the cross bars, and the method I use in operating my improved leaf, and Fig. 6, is a plan view in part diagrammatic showing a part of the frame and the arrangement of leaves, the modified form or extended face being shown on either side.

Referring to the accompanying drawings, 1 indicates the curved face or surface of a head exposed to fire, 2 the slot or opening for air space, 3 the cutting edge of leaf, said cutting edge 3 extending below the top surface of the cross-bars, 8, upon which said leaves are mountedA shows the extended fingers which with relation to the opposite side of the head are preferably staggered, the fingers on one side corresponding in position to the spaces on the opposite side. Along the sides of the head are air spaces 5, formed by the extending fingers l. The shank or body part of the leaf is shown at 6. This shank is webbed, or I shaped in cross section, as shown at 7. .The heads of the shanks extend upwardly and form outwardly projecting fingers on the opposite sides of the head, thus forming a rigid structure, other fingers projecting outwardly from the head on each side thereof. The leaves are preferably mounted on cross bars as shown at 8, and are in turn supported by the frame 9. Through the medium of the rod 10, the bar 11, and the cross bar 8, motion is imparted to the leaves. The operation is obvious from the description. It will also be apparent from the foregoing that as my circular faced leaf has no projection to break up the fire during the process of shaking the grates, as is the case with other types of grate surface, a much smaller grade of coal may be successfully used.

am aware that prior to my invention grate bars have been made with slightly curved surfaces. I therefore do not make such a claim broadly; but

lVhat I do claim as my invention, and desire to secure by Letters Patent, is

1. In combination with cross bars having openings formed therein, grate bar leaves consisting of a shank Lshaped in cross section received in said openings of the cross bar, a head on each shank having an arcshaped outer face, the under side of the head ends and said outer faces meeting to form cutting edges, and fingers projecting in spaced relation outwardly from each side of the heads, said fingers being arranged in staggered relation.

2. In combination with a supporting rocking cross bar having apertures therein, rate bar leaves each formed ofa head and a SlEllllC extending loosely through said apertures, said head having a concave under face and a convex outer face which meet to form cutting edges, said head at its under side resting on said cross bar and being supported thereby, said cutting edges extending considerably below the point of the leaves, support so that the leaves will be held against upward movement during actuation of the cross bar.

In testimony whereof I affix my signature n1 presence of two wltnesses.

J OHN \V. FOWLER, FORBES H. V. EATON. 

